NEW YORK  The federal Environmental Protection Agency (EPA) has pulled back from an investigation into drinking water quality near an oil and gas field in Wyoming after the state said it would extend its own investigation.

"In light of this announcement, we believe that EPAs focus going forward should be on using our resources to support Wyomings efforts, which will build on EPAs monitoring results," acting administrator Bob Perciasepe said in a statement.

Americas Natural Gas Alliance, a group that represents natural gas producers, applauded the decision. "Todays announcement reaffirms that state regulators have the expertise on natural gas operations and are best positioned to oversee our industry," president and chief executive officer Marty Durbin said in a statement.

The EPA started the investigation in 2009 after residents outside Pavillion, Wyo., "reported objectionable taste and odor in their well water," the agency said.

The state intends to conclude its investigation, which will be led by the Wyoming Department of Environmental Quality and the Wyoming Oil and Gas Conservation Commission, and release a final report by Sept. 30 next year.